Liner hanger

Abstract

An improved liner hanger comprises a mandrel having a piston housing and a plurality of spring slots disposed on the outer wall surface of the mandrel. Each spring slot having at least one spring disposed therein. The liner hanger also has a slip housing having a plurality of slips operatively associated therewith, a spring adjustment sleeve, and an adjustment sleeve ring. The location of the spring slots on the outer wall surface of the mandrel permits an increase in the number of springs utilized for setting the liner hanger. The spring adjustment sleeve and adjustment sleeve ring permit easy and safe assembly and disassembly of the liner hanger. Additionally, when actuated to move from its run-in position to its set position, springs, slip housing, and slips all move upward.

1. A liner hanger for securing to the inner wall of a wellbore casing and having an initial run-in position and a set position, the liner hanger comprising:
 a mandrel having an inner wall surface defining a bore and an outer wall surface, the outer wall surface having
 at least one slip pocket, a plurality of spring slots, each spring slot having at least one spring disposed therein, and a piston housing, the piston housing having at least one piston disposed therein, wherein the piston is in fluid communication with the bore; 
 
 a slip housing disposed below the piston housing and each of the spring slots, the slip housing being slidingly engaged with the outer wall surface of the mandrel and having at least one slip operatively associated therewith, each of the at least one slips being disposed within a corresponding slip pocket; and 
 a retainer,
 wherein the slip housing is held in the run-in position by the retainer so that each of the slips is disposed within each of the corresponding slip pockets, and 
 wherein actuation of the piston causes the retainer to release the slip housing allowing each of the plurality of springs to move the slip housing upward axially from the run-in position to the set position which causes each of the slips to move upward axially and radially relative to the corresponding slip pockets and the mandrel to engage the inner wall of the wellbore casing. 
 
 
   
   
     2. The liner hanger of  claim 1 , wherein the mandrel includes a split ring groove and the retainer is a split ring disposed within the split ring groove, the split ring being operatively associated with a key. 
   
   
     3. The liner hanger of  claim 2 , wherein the slip housing includes an inner wall surface having a groove for receiving the split ring and a pocket for receiving the key and wherein the slip housing contacts each of the plurality of springs when the liner hanger is in the run-in position. 
   
   
     4. The liner hanger of  claim 3 , wherein the key is in contact with the piston when the liner hanger is in the run-in position. 
   
   
     5. The liner hanger of  claim 4 , wherein the key is held in place by a shear screw when the liner hanger is in the run-in position. 
   
   
     6. The liner hanger of  claim 5 , wherein the key includes a body, a pair of opposed surfaces, a tab, and a shear screw hole for receiving the shear screw, the pair of opposed surfaces being matingly engaged with a corresponding pair of opposed shoulders on the split ring when the liner hanger is in the run-in position. 
   
   
     7. The liner hanger of  claim 1 , further comprising a spring adjustment sleeve for compressing and maintaining each of the springs within the corresponding spring slots when the liner hanger is in the run-in position. 
   
   
     8. The liner hanger of  claim 7 , wherein the spring adjustment sleeve includes threads on an inner wall surface of the spring adjustment sleeve. 
   
   
     9. The liner hanger of  claim 7 , further comprising an adjustment sleeve ring for securing the spring adjustment sleeve to the mandrel and wherein the spring adjustment sleeve includes a protrusion slidingly engaged with a slot on the mandrel for aligning the spring adjustment sleeve on the mandrel. 
   
   
     10. The liner hanger of  claim 9 , wherein the adjustment sleeve ring includes a set screw for preventing the adjustment sleeve ring from loosening. 
   
   
     11. The liner hanger of  claim 10 , wherein the adjustment sleeve ring includes threads for securing the adjustment sleeve ring to the outer wall surface of the mandrel. 
   
   
     12. The liner hanger of  claim 7 , wherein the spring adjustment sleeve includes a shoulder for abutting each of the springs. 
   
   
     13. The liner hanger of  claim 1 , wherein each of the plurality of slips includes a first end having a T-shaped protrusion that matingly engages with a T-slot in the slip housing. 
   
   
     14. The liner hanger of  claim 1 , wherein the piston housing comprises a piston port having a length and a vent port disposed along the piston port length and in fluid communication with the piston port and an environment outside the mandrel. 
   
   
     15. The liner hanger of  claim 1 , wherein each of the springs includes a spring nail. 
   
   
     16. The liner hanger of  claim 1 , wherein each of the plurality of slips includes a gripping wall surface having pyramidal-shaped teeth. 
   
   
     17. An improved liner hanger having a run-in position and a set position, the improvement comprising:
 a plurality of spring slots disposed on an outer wall surface of a mandrel, at least one of the plurality of spring slots having at least one spring disposed therein,
 wherein each of the at least one springs is held within the corresponding spring slots by a slip housing and a spring adjustment sleeve disposed on the outer wall surface of the mandrel when the liner hanger is in the run-in position, 
 wherein the spring adjustment sleeve includes a shoulder disposed on an inner wall surface of the spring adjustment sleeve, and 
 wherein the inner wall surface of the spring adjustment sleeve includes threads for securing the spring adjustment sleeve to the outer wall surface of the mandrel. 
 
 
   
   
     18. A method of setting a liner hanger within a wellbore casing of a well, the method comprising:
 (a) disposing a liner hanger within a wellbore, the liner hanger having an initial run-in position and a set position and the liner hanger comprising
 a mandrel having an inner wall surface defining a bore and an outer wall surface, the outer wall surface having at least one slip pocket, a split ring groove, a plurality of spring slots, each spring slot having at least one spring disposed therein, and a piston housing, the piston housing having at least one piston disposed therein, wherein the piston is in fluid communication with the bore, and 
 a slip housing disposed below the piston housing and each of the spring slots, the slip housing being slidingly engaged with the outer wall surface of the mandrel and having at least one slip operatively associated therewith, each of the at least one slips having a gripping wall surface and being slidingly engaged within a corresponding slip pocket,
 wherein the slip housing is held in the run-in position by a retainer so that each of the slips is disposed within each of the corresponding slip pockets; 
 
 
 (b) actuating the piston through an increase in pressure in the bore of the mandrel, wherein the actuation of the piston releases the retainer so that the slip housing is permitted to move axially along the outer wall surface of the mandrel and each of the springs is permitted to expand in an upward direction; and 
 (c) expanding in the upward direction each of the springs sufficiently to move the slip housing axially in the upward direction so that each of the plurality of slips move axially in the upward direction causing each of the slips to move in the upward direction and in an outward direction so that the gripping profile surface of each of the slips bites into an inner wall surface of the wellbore casing. 
 
   
   
     19. The method of  claim 18 , wherein each of the slip pockets include at least one groove for receiving at least one slip ramp disposed on at least one of the slips so that during step (c) movement of each of the slips is guided by the at least one groove.